In the process of manufacturing a semiconductor device, a plasma processing device has been broadly used. The plasma processing device has an upper electrode and a lower electrode which are disposed so as to face one another in a processing chamber. In such a plasma processing device, by making the processing gas in the processing chamber be plasma by applying high-frequency electric power to the upper electrode, plasma processing is carried out on an object to be processed on the lower electrode.
An upper electrode unit in which the upper electrode is disposed has a complex structure in which a shield box, which accommodates a feeding member such as a feeding bar or the like feeding electrode high-frequency electric power to the upper electrode, and a matching box in which a matching machine or the like is accommodated, and a processing gas supplying system, and the like, are integrally assembled. Therefore, the upper electrode unit has been a unit such that, on the whole, the weight thereof is heavy and the volume thereof also is large.
Accordingly, when maintenance such as cleaning of the upper electrode or the interior of the processing chamber is carried out, there is the need for a worker to carry out the maintenance after the upper electrode unit is disassembled into members having weights and sizes which can be dealt with. Further, after the maintenance is completed, there is the need to assemble the respective members into the upper electrode unit again.
In this way, conventionally, disassembling and assembling of the device had to be carried out each time maintenance was carried out. As a result, there was the problem that the operation efficiency of the device deteriorated. Further, at the time of assembly, arranging the positions of the respective members must be accurately carried out. Therefore, there were the problems that the work was complicated, and further, the working time increased. Moreover, generally, the shield box and the matching box are disposed at a height at which it is difficult for the worker to work. Therefore, the worker must carry out the work of mounting and removing of the respective members at a difficult position. As a result, there was the problem that a burden was imposed on the worker.
The upper electrode is mounted to a member such as a cooling plate supporting the upper electrode by a fastening means such as metallic screws or the like. Therefore, in order to prevent abnormal discharge, the mounting portion of the fastening means, such as the periphery of the upper electrode or the like, is covered with an insulating shielding ring. Conventionally, the shielding ring is mounted to the cooling plate by a fastening means. However, depending on the structure of the fastening means, if the coefficients of linear expansion of the shielding ring and the cooling plate are different, different warpings arise at the shielding ring and the cooling plate due to heat at the time of processing, and as a result, there have been cases in which a load is applied to the fastening means and the fastening means is damaged.
Further, conventionally, the shielding ring is provided so as to simply overlap on the processing chamber side surface of the upper electrode. Therefore, a step arises between the upper electrode and the shielding ring, and this has been a cause of disturbing the plasma. As a result, there is the problem that the uniformity of processing cannot be improved.
The present invention has been achieved in consideration of the above-described problems which the conventional art has, and an object of the present invention is to provide a processing device and a method of maintaining the device, a mechanism and a method for assembling processing device parts, and a lock mechanism and a method for locking the lock mechanism, which can solve the above-described problems and other problems and which are novel and improved.